1. Field of the Invention
The invention relates to a roof arrangement for a convertible with a rigid front roof part and a rigid rear part, in which the rear part is swung over the front roof part and the two roof parts are lowered as a package into a rear storage compartment for the roof.
2. Description of Related Art
German Patent DE 44 35 222 C1 and corresponding U.S. Pat. No 5,769,483 show a roof arrangement for a convertible in which the rear part of the roof arrangement is swung over a front roof part and then the stacked roof parts are lowered rearwardly into a rear storage compartment for the roof. This way of stacking the front roof part and the rear part on top of one another, the two roof components coming to rest on top of one another in the same direction with respect to their arched curvature, has the advantage that the roof parts stacked into a package are arranged in a very space-saving manner and therefore require less space in the rear stowage space of the motor vehicle. To stack the roof parts on top of one another and to lower them into the rear stowage space or the storage compartment for the folding roof, in one embodiment, there is a mechanism in which a triangular lever is coupled to the body and can be driven via a drive cylinder. Between the triangular lever and the rear part there are two hydraulic cylinders and one telescoping guide. Furthermore, there is a pivot lever which, on the one hand, is coupled in the rear area of the body, and on the other hand, is connected to the rear end section of the roof part. When the roof arrangement is opened, first the rear part is moved radially outward by extending the two hydraulic cylinders and then the rear part is swung up over the roof part by a special locking means. At this point, the drive cylinder is retracted again, the roof arrangement being swung around a multi-joint to the rear into the stowage space. The multi-joint is formed, here, by one of the two hydraulic cylinders, a triangular lever, a drive cylinder and the pivoting lever. One of the two hydraulic cylinders must be released in this pivoting motion in order not to prevent pivoting motion into the stowage space because the two hydraulic cylinders, together with the pivoting lever, would otherwise represent a mechanical redundancy. The two hydraulic cylinders, together with the triangular lever and the drive cylinder, therefore, represent a multi-joint connection between the roof arrangement and the body.
In another embodiment, the rear part is coupled to the body via a four-bar mechanism with two levers. Since the rear part is swung by driving the four-bar mechanism over the roof part and is interlocked with the roof part, the stacked roof arrangement is swung to the rear into the storage compartment for the folding roof via the two levers of the four-bar mechanism and the other pivoting lever which is coupled between the roof part and the body. This arrangement of three levers between the stacked roof arrangement and the body represents a mechanical redundancy in which a pivoting motion is only possible when either a certain arrangement of the levers is chosen or one of the levers is detachably coupled during certain phases of motion.
The mechanical embodiments shown in German Patent DE 44 35 222 C1 and corresponding U.S. Pat. No. 5,769,483 are accordingly made very complex, and a host of drives is necessary to execute the motion for opening and closing the roof arrangement.
Therefore, an object of this invention is to devise a roof arrangement of the initially described type in which the inherently complex sequence of motions for opening and closing the roof arrangement is achieved by a simple mechanism with as few drive units as possible.
This object is achieved by a roof arrangement in which a forced control mechanism has a single lever which is located between the rear roof part and the rear body and which is connected at one end via a first pivot joint to the rear roof part and is coupled at another end to the body. For a convertible with a rigid front roof part, a rigid rear part and a storage compartment for the folding top located in the rear area of the vehicle for holding the roof arrangement and a forced control mechanism for opening and closing the roof arrangement, this approach calls for the fact that, to open the roof arrangement, first the rear part is swung over the front roof part and then the front roof part together with the rear roof part stacked over it are swung into the storage compartment for the folding roof, the forced control mechanism having a single lever which is located between the front roof part and the rear roof part and which is connected at one end, via the first pivot joint, to the rear part and is coupled at the other end to the body.
By providing a single lever between the rear part and the body, a simple mechanism is provided which, on the one hand, allows the rear part to be easily swung up over the front roof part, and on the other hand, after pivoting up, additional connecting levers need not be unlocked to enable pivoting of the entire stacked roof arrangement into the storage compartment for the folding roof.
In one embodiment, the first pivot joint is located in the line of gravity of the rear part. In this way, the rear part can be easily swung over the roof part. The rear part can be folded out especially advantageously by a guide means between the rear section of the front roof part and the top section of the rear part. The guide means has the advantage that the top end section of the rear part can be guided very closely and accurately with little mechanical effort over the rear section of the front roof part.
In one embodiment, the end section of the lever coupled to the body has an inner mounting point and an outer mounting point which is spaced away from the inner mounting point, and they can be selectively connected via a switching means either to a second pivot bearing or to a third pivot bearing. In this way, it is advantageously possible, on the one hand, to optimally fix the coupling point for pivoting up the rear part, and on the other hand, to optimally fix the coupling point for lowering the stacked roof arrangement for the lever. Furthermore, when using a lifting cylinder as the drive for the lever, the direction of rotation of the lever can be advantageously reversed at the same time with reversing from the one to the other pivot joint when the lifting cylinder is coupled between the inner and the outer mounting point.
In one advantageous embodiment, the switching means for reversing from the connection of the inner mounting point to the second pivot bearing to the connection of the outer mounting point to the third pivot bearing and vice versa has a locking mechanism, the lock being guided via a crank and the lifting cylinder being connected to the lever via the lock such that the lifting cylinder also drives the lock motion. The special advantage of this arrangement is that the lifting cylinder, during the switching process, does not cause any motion of the roof arrangement so that, simultaneously with the switching process, the rear part can be interlocked with the roof part in the stacked arrangement and the roof part with the windshield can be unlocked. In this way, also a precision transition from swinging up the rear part to lowering of the stacked roof arrangement is also possible without the lifting cylinder having to change its speed. The lifting cylinder can rather easily move from one end position to the other end position with a constant speed.
Preferred embodiments of the invention are described below with reference to the drawings.